JP6646034B2 - Robot system - Google Patents

Description

  The present invention relates to a robot system, and more particularly, to a robot system that inspects an object to be inspected based on an image.

2. Description of the Related Art Conventionally, there has been known a system in which an image of an object to be inspected is acquired by a camera attached to a robot, and length measurement and appearance inspection of the object to be inspected are performed based on the image (for example, see Patent Documents 1 and 2). ).
On the other hand, there is known a system in which one camera is attached to a plurality of robots in order to measure the relative position and orientation between a plurality of sets of robots and an object to be measured using one camera ( For example, see Patent Document 3.)

JP 2010-076056 A JP 2005-131761 A Japanese Patent No. 4137762

  In inspection using images as disclosed in Patent Documents 1 and 2, work may be performed by a plurality of robots in order to reduce cycle time. When cameras are attached to multiple robots and images of the inspection object are acquired by different cameras, differences in the characteristics of the optical system such as lens distortion affect the images, and the images used for inspection There is an inconvenience that quality varies among robots. Particularly strict inspections require that the image quality be constant. Patent Document 3 does not disclose that a single camera is shared by a plurality of robots in an inspection.

  The present invention has been made in view of the above circumstances, and provides a robot system capable of performing an inspection using images of a constant quality in an inspection using images by a plurality of robots. Aim.

In order to achieve the above object, the present invention provides the following means.
One embodiment of the present invention is a plurality of robots, an imaging unit that can be attached to and detachable from each of the plurality of robots and acquires an image of an inspection object, and each of the plurality of robots is connected to the plurality of robots. A plurality of image inspection units for inspecting the inspection object based on an image acquired by an imaging unit, wherein the imaging unit includes optical characteristic data indicating optical characteristics of the imaging unit and is inspected by the image inspection unit. A robot system that holds image inspection data used in the image inspection and transmits the image inspection data to the image inspection unit connected to the robot to which the imaging unit is attached.

  According to this aspect, the imaging unit attached to the robot is positioned and positioned with respect to the inspection object by the operation of the robot, and an image of the inspection object is acquired by the imaging unit. The quality of the acquired image is affected by the optical characteristics of the imaging unit. For example, an aberration resulting from distortion of a lens of the imaging unit occurs in an image. The imaging unit holds image inspection data including the optical characteristic data of the imaging unit, and the image inspection data is transmitted from the imaging unit to the image inspection unit of the robot to which the imaging unit is connected. Therefore, the image inspection unit obtains an image in which the influence of the optical characteristics of the imaging unit is eliminated by performing processing such as aberration correction on the image based on the optical characteristic data, and uses the obtained image for image inspection. be able to.

  In this case, the imaging unit can be attached to and detached from a plurality of robots, and the plurality of robots perform an image acquisition operation while sequentially using the same imaging unit. Therefore, the plurality of image inspection units connected to the plurality of robots can use an image obtained by the same imaging unit and subjected to processing such as aberration correction based on the same optical characteristic data for the inspection. . Thus, images of a fixed quality can be used for inspection by all image inspection units, and the accuracy of inspection can be stabilized.

In the above aspect, a tool changer for attaching the imaging unit to the robot may be provided.
By using the tool changer, it is possible to cause the robot to perform an operation of attaching and detaching the imaging unit to and from the robot. Further, the tool connected to the robot can be easily exchanged between the imaging unit and another tool.

In the above aspect, a transmission cable for transmitting the image inspection data is connected to the imaging unit and the image inspection unit, respectively, and the tool changer is configured to transmit the transmission cable of the imaging unit and the transmission of the image inspection unit. You may have the connection part which connects with a cable.
When the imaging unit is attached to the robot via the tool changer, the transmission cable of the imaging unit and the transmission cable of the image inspection unit are mutually connected by the connection unit. When the imaging unit is removed from the robot, the transmission cable of the imaging unit and the transmission cable of the image inspection unit are disconnected from each other by the connection unit. Thus, the work of connecting and disconnecting the transmission cable when attaching and detaching the imaging unit to and from the robot can be eliminated.

In the above aspect, a production management device may be provided that controls the plurality of robots so that the plurality of robots sequentially perform the attaching operation and the removing operation of the imaging unit.
With this configuration, the robot can perform attachment and detachment of the imaging unit to and from the robot and transfer of the imaging unit between the robots.

  Advantageous Effects of Invention According to the present invention, in an inspection using images by a plurality of robots, there is an effect that an inspection can be performed using an image of a certain quality.

1 is an overall configuration diagram of a robot system according to an embodiment of the present invention. 3 is a flowchart illustrating an image inspection operation of the robot system in FIG. 1.

Hereinafter, a robot system 1 according to an embodiment of the present invention will be described with reference to the drawings.
The robot system 1 according to the present embodiment controls the position and orientation of the camera unit 2 with respect to the inspection object A by the robots 11 and 12, and based on the image of the inspection object A acquired by the camera unit 2, The inspection such as the length measurement and the appearance inspection of A is executed.

  As shown in FIG. 1, the robot system 1 includes a plurality of robots 11 and 12, one camera unit (imaging unit) 2 shared by the plurality of robots 11 and 12, and a camera unit 2. The tool changer 3 attached to the robots 11 and 12, a plurality of robot controllers 41 and 42 connected to the robots 11 and 12, and a plurality of image processing devices connected to the robot controllers 41 and 42 (image (Inspection units) 51 and 52, and a production management device 6 for managing and controlling the entire robot system 1.

  FIG. 1 shows, as an example, a robot system 1 in which one camera unit 2 is shared by two robots 11 and 12, but one camera unit 2 is shared by three or more robots. May be configured to be performed.

  The robots 11, 12 are any type of industrial robot commonly used for image inspection. FIG. 1 shows six-axis articulated robots 11 and 12 as an example. The robots 11 and 12 have arms 11a and 12a, and mounting flanges 11b and 12b provided at the tips of the arms 11a and 12a and to which the camera unit 2 is mounted via a tool changer 3, respectively.

The camera unit 2 includes a camera 2a for acquiring an image of the inspection object A, and a storage device 2b.
Image inspection data used for image processing by the image processing devices 51 and 52 is stored in the storage device 2b in advance. The image inspection data includes optical characteristic data indicating the optical characteristics of the camera 2a, such as the focal length and lens distortion. The image inspection data includes other data necessary for image processing by the image processing devices 51 and 52, for example, a template image of the inspection object A for recognizing the inspection object A in the image and a data of the inspection object A. Position information and the like of the inspection site may be further included.

An operation program for controlling operations of the robots 11 and 12 and the camera unit 2 during image inspection is stored in the storage device 2b in advance. The storage device 2b stores an image obtained by the camera 2a.
In case that the image inspection data and the operation program stored in the storage device 2b are damaged, the image inspection data and the backup data of the operation program are stored in another storage device included in the robot system 1 (for example, production management). (A storage device of the device 6).

  The tool changer 3 includes a robot-side adapter 3a attached to each of the mounting flanges 11b and 12b, and a tool-side adapter 3b attached to the camera unit 2. The robots 11 and 12 connect and disconnect the robot-side adapter 3a and the tool-side adapter 3b by sending pneumatic or electric signals to the robot-side adapter 3a, thereby attaching the camera unit 2 to the mounting flanges 11b and 12b. And remove.

  In addition to the camera unit 2, other tools to which the tool-side adapter 3b is attached (for example, a hand for handling the inspection object A and a tool for processing the inspection object A) are prepared. However, a plurality of types of work may be performed in order while exchanging the camera unit 2 with another tool.

The adapters 3a and 3b are provided with connection portions 71 and 72 that are connected to each other when the adapters 3a and 3b are connected to each other. The image processing device 51 is connected to the connection portion 71 of the robot-side adapter 3a of the robot 11 by a transmission cable 81. The image processing device 52 is connected to the connection portion 71 of the robot-side adapter 3 a of the robot 12 by a transmission cable 81. The camera unit 2 is connected to the connection part 72 of the tool-side adapter 3b by a transmission cable 82.
Therefore, when the camera unit 2 is connected to the mounting flange 11 b via the tool changer 3, the camera unit 2 is automatically connected to the image processing device 51 by the transmission cables 81 and 82, and the mounting flange is connected via the tool changer 3. When the camera unit 2 is connected to 12b, the camera unit 2 is automatically connected to the image processing device 52 by transmission cables 81 and 82.

  When the camera unit 2 is connected to the image processing device 51 or 52, power is supplied from the image processing device 51 or 52 to the camera unit 2 via the transmission cables 81 and 82, and the camera unit 2 activated by the power supply is The image inspection data and the operation program are transmitted to the image processing device 51 or 52 via the transmission cables 81 and 82. Then, the image acquired by the camera 2a is transmitted from the camera unit 2 to the image processing device 51 or 52 via the transmission cables 81 and 82.

  When the camera unit 2 acquires a large number of images in a short time while the robots 11 and 12 operate at high speed, it is necessary to transmit a large number of images from the camera unit 2 to the image processing devices 51 and 52 in a short time. There is. Therefore, it is preferable to use the transmission cables 81 and 82 capable of high-speed transmission.

  Each of the robot controllers 41 and 42 includes a storage device (not shown) and a processor (not shown) such as a central processing unit. Various programs for controlling the operations of the robots 11 and 12 are stored in the storage device. When the processor operates according to the program, control of the robots 11 and 12 by the robot control devices 41 and 42 is realized.

  The robot controllers 41 and 42 cause the robots 11 and 12 to perform an operation of attaching the camera unit 2 to the attachment flanges 11b and 12b and an operation of removing the camera unit 2 from the attachment flanges 11b and 12b. For example, in the mounting operation, the robots 11 and 12 operate the arm 11a to move the mounting flanges 11b and 12b to a predetermined position where the camera unit 2 is arranged, and mount the camera unit 2 on the mounting flanges 11b and 12b. . In the detaching operation, the robots 11 and 12 operate the arm 11a to move the mounting flanges 11b and 12b to a predetermined position, remove the camera unit 2 from the mounting flanges 11b and 12b, and place the camera unit 2 at the predetermined position. I do.

  After the camera unit 2 is mounted on the mounting flanges 11b and 12b, the robot controllers 41 and 42 receive the operation programs transmitted from the camera unit 2 to the image processing devices 51 and 52 from the image processing devices 51 and 52. Then, the operation program is stored in the storage device. Next, the robot controllers 41 and 42 control the robots 11 and 12 and the camera unit 2 connected to the robots 11 and 12 via the tool changer 3 according to the operation program. Specifically, the robot controllers 41 and 42 move the arms 11 a and 12 a of the robots 11 and 12 to dispose the camera unit 2 at a predetermined position and a predetermined posture with respect to the inspection object A, and the camera 2 a To execute image acquisition of the inspection object A.

  The imaging conditions such as the relative positions of the robots 11 and 12 and the camera unit 2, the imaging distance from the camera unit 2 to the inspection object A, and the inclination of the table on which the inspection object A is placed are different between the robots 11 and 12. Can be different. When such a difference in the imaging conditions exists between the robots 11 and 12, calibration data for correcting the image of the inspection object A acquired by the camera 2a according to the imaging conditions is transmitted to the robot controller. The information may be stored in the storage devices 41 and 42 in advance. The calibration data is transmitted from the robot control devices 41 and 42 to the image processing devices 51 and 52 and used by the image processing devices 51 and 52.

The image processing devices 51 and 52 supply power to the camera unit 2 connected by the transmission cables 81 and 82.
Each of the image processing devices 51 and 52 includes a storage device (not shown) and a processor (not shown) such as a central processing unit. The storage device stores an image processing program for image inspection. When the image processing devices 51 and 52 receive the image of the inspection object A from the camera unit 2, the processor performs image processing using the data for image inspection on the images according to the image processing program. Image inspection processing of the inspection object A is realized.

In the image acquired by the camera 2a, aberrations are generated due to distortion of the lens of the camera 2a and the like. In the image inspection process of the inspection object A, first, the image processing devices 51 and 52 correct the image aberration based on the optical characteristic data of the camera 2a. Image inspection data transmitted from the camera unit 2 to the image processing devices 51 and 52 includes calibration data for aberration correction, and the image processing devices 51 and 52 perform aberration correction using the calibration data. You may.
After the aberration correction, the image processing devices 51 and 52 may further correct the image based on the calibration data from the robot control devices 41 and 42.

Next, the image processing devices 51 and 52 inspect the inspection object A based on the image subjected to the aberration correction. For example, the image processing devices 51 and 52 recognize the inspection object A in the image by template matching using the template image, and detect the inspection region of the inspection object A by edge extraction or the like based on the positional information of the inspection region. Then, the length of the detected inspection site is measured.
Although FIG. 1 shows image processing devices 51 and 52 that are separate from the robot control devices 41 and 42, the image processing devices 51 and 52 are realized as a part of the functions of the robot control devices 41 and 42. May be done.

  The production management device 6 is connected to the robot controllers 41 and 42 by wiring (not shown). The production management device 6 controls the robot controllers 41 and 42 so that the two robots 11 and 12 sequentially perform the mounting operation and the removing operation of the camera unit 2.

Next, the operation of the robot system 1 during the image inspection of the inspection object A will be described with reference to FIG.
When the first robot 11 attaches the camera unit 2 to the attachment flange 11b via the tool changer 3 (step S1), power supply from the image processing device 51 to the camera unit 2 is started, and the camera unit 2 transfers the power to the tool changer 3 from the camera unit 2. The data for image inspection is transmitted to the image processing device 51 via (step S2). In step S2, the operation programs of the robot 11 and the camera unit 2 are transmitted from the camera unit 2 to the robot controller 41 via the image processing device 51, and the operation programs are set in the robot controller 41.

Next, the robot controller 41 causes the first robot 11 and the camera unit 2 to acquire an image of the inspection object A according to the operation program (step S3). Specifically, the camera unit 2 is arranged at a predetermined position in a predetermined posture by the operation of the arm 11a, and the camera 2a acquires an image of the inspection object A. The acquired image is transmitted from the camera unit 2 to the image processing device 51.
Next, in the image processing device 51, aberration correction processing is performed on the image of the inspection object A based on the optical characteristic data of the camera 2a, and subsequently, image inspection processing such as length measurement or appearance inspection of the inspection object A is performed. Is executed (step S4).
Next, the power supply from the image processing device 51 to the camera unit 2 is stopped, and the first robot 11 removes the camera unit 2 from the mounting flange 11b (step S5). After step S5, the robot 11 performs an operation such as transporting the inspection object A, for example.

  Next, when the second robot 12 attaches the camera unit 2 to the attachment flange 12b via the tool changer 3 (step S6), power supply from the image processing device 52 to the camera unit 2 is started, and The image inspection data is transmitted to the image processing device 52 via the tool changer 3 (step S7). In step S7, similarly to step S2, the operation program of the robot 12 and the camera unit 2 is transmitted from the camera unit 2 to the robot controller 42, and the operation program is set in the robot controller 42.

Next, as in step S3, the robot controller 42 causes the second robot 12 and the camera unit 2 to acquire an image of the inspection object A according to the operation program (step S8).
Next, similarly to step S4, the image processing apparatus 52 performs an aberration correction process on the image of the inspection object A based on the optical characteristic data of the camera 2a. Image inspection processing such as inspection is performed (step S9).
Next, the power supply from the image processing device 52 to the camera unit 2 is stopped, and the second robot 12 removes the camera unit 2 from the mounting flange 12b (step S10). After step S10, the robot 12 performs operations such as transporting the inspection object A, for example.
Hereinafter, steps S1 to S10 are repeated.

For example, when a large number of images are acquired in step S3, image processing by the image processing device 51 in step S4 may require time (for example, several seconds to tens of seconds). In such a case, the removal of the camera unit 2 in step S5 is performed immediately after step S3, and the image processing device 51 in step S4 is performed while the second robot 12 is performing the image acquisition work in step S8. May be executed. As described above, by executing the image processing by the image processing device 51 and the image acquisition work by the second robot 12 in parallel, the cycle time can be reduced.
Similarly, immediately after step S8, the removal of the camera unit 2 in step S10 is executed, and the image acquisition work by the first robot 11 in the next step S4 and the image processing by the image processing device 52 in step S9 are performed in parallel. May be performed.

  As described above, the camera 2a has unique optical characteristics such as lens distortion. Therefore, when two camera units are prepared for the robot 11 and the robot 12, a difference occurs in the quality of the image of the inspection object A obtained by the two camera units, and the two image processing devices 51, A difference due to a difference in image quality may also occur in the image inspection result by 52. Therefore, for example, in the strict inspection of the inspection object A, it is required that the quality of the image is constant.

  According to the present embodiment, one camera unit 2 that holds the optical characteristic data of the camera 2a is shared by a plurality of robots 11 and 12. Then, the optical characteristic data is transmitted from the camera unit 2 to the image processing devices 51 and 52 of the robots 11 and 12 to which the camera unit 2 is attached. Therefore, the plurality of image processing apparatuses 51 and 52 can use the images acquired by the same camera 2a and corrected based on the same optical characteristic data for the image inspection processing. That is, there is an advantage that the image inspection can be performed by using a plurality of image processing apparatuses 51 and 52 using images of a fixed quality, and the accuracy of the image inspection can be stabilized.

Further, since only one image inspection data is created and managed for a plurality of sets of robots 11 and 12 and image processing devices 51 and 52, the work required for creating and managing the image inspection data can be reduced. There is an advantage that can be.
Further, since only one camera unit 2 is required for a plurality of robots 11 and 12, there is an advantage that the product cost of the robot system 1 can be reduced.

  Further, when one camera unit 2 is shared by a plurality of robots 11 and 12, wiring of a cable connecting the camera unit 2 and the image processing devices 51 and 52 becomes a problem. That is, when the camera unit 2 is shared by the plurality of robots 11 and 12 while the camera unit 2 is connected to the plurality of image processing apparatuses 51 and 52 by cables, the operating range of the robots 11 and 12 is controlled by the cables. Cables may be restricted or interfere with the operating robots 11, 12. According to the present embodiment, by using the tool changer 3 having the connection portions 71 and 72 for attaching the camera unit 2 to the robots 11 and 12, the problem of the cable can be solved.

In the present embodiment, the image inspection data is transmitted from the camera unit 2 to the image processing devices 51 and 52 by the transmission cables 81 and 82. Instead, the image inspection data is transmitted wirelessly. Is also good.
In the present embodiment, the camera unit 2 is attached to the robots 11 and 12 via the tool changer 3, but the camera unit 2 may be directly attached to the attachment flanges 11b and 12b instead.

In the present embodiment, the attachment and detachment of the camera unit 2 to and from the robots 11 and 12 are performed by the robots 11 and 12 themselves, but may be performed by an operator instead.
In the present embodiment, the case where the two robots 11 and 12 arranged close to each other go for the camera unit 2 has been described as an example, but the production management device 6 is attached to the current camera unit 2. A transfer device or a transfer robot (not shown) may be controlled so that the camera unit 2 is transferred from the robot that is currently using the camera unit 2 to the robot that uses the camera unit 2 next.

Reference Signs List 1 robot system 11, 12 robot 11a, 12a arm 11b, 12b mounting flange 2 camera unit (imaging unit)
2a Camera 2b Storage device 3 Tool changer 3a Robot-side adapter 3b Tool-side adapter 41, 42 Robot controller 51, 52 Image processor (image inspection unit)
6 Production management device 71, 72 Connection part 81, 82 Transmission cable A Inspection object

Claims (4)

With multiple robots,
An imaging unit that can be attached to and detached from each of the plurality of robots and acquires an image of an inspection object;
A plurality of image inspection units connected to the plurality of robots, respectively, to inspect the inspection object based on an image acquired by the imaging unit,
The imaging unit holds image inspection data used for inspection by the image inspection unit including optical characteristic data indicating optical characteristics of the imaging unit, and is connected to the robot to which the imaging unit is attached. A robot system for transmitting the image inspection data to the image inspection unit.   The robot system according to claim 1, further comprising a tool changer that attaches the imaging unit to the robot. Transmission cables for transmitting the image inspection data are connected to the imaging unit and the image inspection unit, respectively.
The robot system according to claim 2, wherein the tool changer includes a connection unit that connects the transmission cable of the imaging unit and the transmission cable of the image inspection unit.   4. The robot system according to claim 1, further comprising a production management device that controls the plurality of robots so that the plurality of robots sequentially perform the mounting operation and the removing operation of the imaging unit. 5. .

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